package src.reflectdemo;

import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

/**
 * @Author 12629
 * @Description：
 */
public class ReflectDemo {
    //如何通过反射 实例化对象
    public static void reflectNewInstance() {
        Class<?> c1;
        try {

            c1 = Class.forName("reflectdemo.Student");
            Student student = (Student) c1.newInstance();
            System.out.println(student);

        } catch (ClassNotFoundException e) {
            throw new RuntimeException(e);
        } catch (InstantiationException e) {
            throw new RuntimeException(e);
        } catch (IllegalAccessException e) {
            throw new RuntimeException(e);
        }
    }

    // 反射私有的构造方法  屏蔽内容为获得公有的构造方法
    public static void reflectPrivateConstructor() {
        Class<?> c1;
        try {
            c1 = Class.forName("reflectdemo.Student");

            Constructor<Student> con =
                    (Constructor)c1.getDeclaredConstructor(String.class,int.class);

            con.setAccessible(true);

            Student student = con.newInstance("zhangsan",18);

            System.out.println(student);

        } catch (ClassNotFoundException e) {
            throw new RuntimeException(e);
        } catch (NoSuchMethodException e) {
            throw new RuntimeException(e);
        } catch (InvocationTargetException e) {
            throw new RuntimeException(e);
        } catch (InstantiationException e) {
            throw new RuntimeException(e);
        } catch (IllegalAccessException e) {
            throw new RuntimeException(e);
        }
    }

    // 反射私有属性
    public static void reflectPrivateField() {
        Class<?> c1;
        try {
            c1 = Class.forName("reflectdemo.Student");
            Field field = c1.getDeclaredField("name");
            field.setAccessible(true);

            Student student = (Student) c1.newInstance();

            field.set(student,"wangwu");

            System.out.println(student);

        } catch (ClassNotFoundException e) {
            throw new RuntimeException(e);
        } catch (NoSuchFieldException e) {
            throw new RuntimeException(e);
        } catch (InstantiationException e) {
            throw new RuntimeException(e);
        } catch (IllegalAccessException e) {
            throw new RuntimeException(e);
        }
    }

    // 反射私有方法
    public static void reflectPrivateMethod() {
        Class<?> c1;
        try {
            c1 = Class.forName("reflectdemo.Student");
            Method method = c1.getDeclaredMethod("function",String.class);

            method.setAccessible(true);

            Student student = (Student) c1.newInstance();

            method.invoke(student,"我是一个参数");

            //System.out.println(student);

        } catch (ClassNotFoundException e) {
            throw new RuntimeException(e);
        } catch (NoSuchMethodException e) {
            throw new RuntimeException(e);
        } catch (InstantiationException e) {
            throw new RuntimeException(e);
        } catch (IllegalAccessException e) {
            throw new RuntimeException(e);
        } catch (InvocationTargetException e) {
            throw new RuntimeException(e);
        }
    }

    public static void main(String[] args) {
        //reflectNewInstance();
        //reflectPrivateConstructor();
        //reflectPrivateField();
        reflectPrivateMethod();
    }
}
